public class Main {
    public static void main(String[] args) {
        int i = 10;
        Integer ii = i;//自动装箱
        Integer ij = (Integer) i;//自动装箱，后面的(Integer)可有可无

        int j = ii;//自动拆箱
        int k = (int)ii;//自动拆箱，后面的(int)可有可无
    }
}
